Even if he had said it, it was hyperbole.
However; the actuality is this:
https://www.guns.com/news/2020/11/17/data-us-has-434-million-guns-20m-ars-150m-mags
To point out the fallacy of this, the AR-15 didn’t even exist back then... :P
Also, great, we have a lot of guns. So did Australia. Look what happened to them.